JPH05106051A - Plasma treating apparatus - Google Patents

Abstract

PURPOSE:To generate plasma uniform in density over a wide area. CONSTITUTION:At the time of supplying a reactive gas to a plasma chamber (11) in which the body to be treated has been arranged, converting the above reactive gas into plasma and executing prescribed treatment to the body (13) to be treated, electric power in accordance with the number of coilings of coils (20 to 24) for at least two electromagnets arranged around the upper end part and lower end part of the plasma chamber (11) is supplied by power source feeding means (26) to generate a magnetic field uniform in magnetic flux density in the plasma chamber (11), by which plasma uniform in density is generated over a wide area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus applied to plasma etching, thin film formation and the like.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a plasma processing apparatus applied to an etching process. A sample table 2 is provided below the processing chamber 1, and an object to be processed 3 such as a semiconductor wafer is placed on the sample table 2. An ionization chamber 4 is formed in the upper part of the processing chamber 1, a gas introduction pipe 5 is connected to the ionization chamber 4, and a magnetic coil 6 is provided on the outer circumference of the ionization chamber 4.
Is provided. A refractory metal mesh 7 having a fine structure is provided inside the processing chamber 1.

With such a configuration, the reactive gas is supplied from the gas introduction pipe 5, and the reactive ions are generated, that is, turned into plasma, in the ionization chamber 4. The reactive ions move inside the processing chamber 1 while being dragged by the electrons along the divergent magnetic field formed by the magnetic coil 6. On this occasion,
The density of the reactive ions is made uniform by the refractory metal mesh 7 arranged perpendicularly to the traveling direction. As a result, the ion beam with which the target object 3 is irradiated has a uniform density, and as a result, the target object 3 is uniformly etched.

By the way, when etching a semiconductor wafer having a large area as the object 3 to be processed,
Plasma having a uniform density must be generated over a region corresponding to the area of the semiconductor wafer. However, it is difficult to generate plasma of uniform density over a wide area by the magnetic coil 6 provided on the outer circumference of the ionization chamber 4.

[0005]

As described above, it is difficult to generate a plasma having a uniform density over a wide area. Therefore, an object of the present invention is to provide a plasma etching processing apparatus capable of generating plasma with a uniform density over a wide area.

[0006]

In a plasma processing apparatus for supplying a reaction gas to a plasma chamber in which an object to be processed is placed and converting the reaction gas into a plasma to perform a predetermined process on the object to be processed, an upper end of the plasma chamber And at least two electromagnet coils disposed around the lower part and the lower end, and power supply means for supplying electric power according to the number of turns of these electromagnet coils to generate a magnetic field having a uniform magnetic flux density in the plasma chamber. The plasma processing apparatus is intended to achieve the above object.

[0007]

By providing such means, when the reaction gas is supplied to the plasma chamber in which the object to be processed is placed and the reaction gas is turned into plasma to perform the predetermined processing on the object to be processed, Of electric power corresponding to the number of turns of at least two electromagnet coils arranged around the upper end and the lower end of the plasma generator to generate a magnetic field having a uniform magnetic flux density in the plasma chamber, and thereby to generate a wide area. A uniform density plasma is generated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a plasma processing apparatus applied to etching. The processing chamber 10 is divided into a plasma chamber 11 and an etching chamber 12, of which the etching chamber 1
In FIG. 2, an object to be processed 13 such as a semiconductor wafer is placed on a sample table (not shown).

A gas inlet pipe 14 is provided at the upper part of the processing chamber 10.
And the exhaust pipe 15 is connected to the lower part,
A waveguide 16 is connected to the upper part of the processing chamber 10. Of these, the gas introduction pipe 14 supplies the reaction gas to the processing chamber 10.
The exhaust pipe 15 is for supplying the gas after treatment to the exhaust system. The waveguide 16 is connected to the processing chamber 10 by providing a seal 17 made of quartz glass, for guiding the microwave into the processing chamber 10. A nozzle plate 18 separates the plasma chamber 11 and the etching chamber 12 from each other. The nozzle plate 18 has a plurality of nozzle holes 19 formed therein.

On the other hand, electromagnet coils 20 to 24 are installed on the outer periphery of the processing chamber 10. Of these coils 20 to 24 for electromagnet, the coils 20 and 24 for electromagnet are arranged on the outer periphery of the upper end portion and the lower end portion of the plasma chamber 11, and the coils 21 to 23 for electromagnet are placed between the coils 20 and 24 for electromagnet. It is evenly located.

The electromagnet coils 20 to 24 are provided in parallel with a coil bobbin 25 as shown in FIG. A case where the shape of the coil bobbin 25 is applied to a 6-inch semiconductor wafer will be described. For example, the coil inner diameter a is 200 mm, the outer diameter b is 400 mm, and the height c is 120 mm. ing. Then, for example, the electromagnet coil 2
Nos. 0 and 24 have 1800 turns, outer diameter is 400 mm, and height is 17
and the number of turns of the electromagnet coils 21 and 45 is 45 mm.
The outer diameter is 250 mm and the height is 17 mm in four turns. The electromagnet coil 22 has 180 turns and the outer diameter is 220 mm and the height is 17 mm.
formed to mm. That is, each electromagnet coil 2 having the same number of turns symmetrically with respect to the electromagnet coil 22 in the vertical direction.
0, 24 and 21, 23 are arranged. A DC power supply 26 is connected to the electromagnet coils 20 to 24 so that the same voltage is applied. Next, the operation of the device configured as described above will be described.

The reaction gas is supplied to the inside of the plasma chamber 11 through the gas introduction pipe 14, and at the same time, the microwave is guided to the inside of the plasma chamber 11 by the waveguide 16. As a result, the reaction gas in the plasma chamber 11 is excited by microwaves and turned into plasma.

On the other hand, the same voltage is applied from the DC power supply 26 to the electromagnet coils 20 to 24, respectively. As a result, a magnetic field having a uniform magnetic flux density is formed in the plasma chamber 11 by the electromagnet coils 20 to 24. That is, as shown in FIG. 3, magnetic fields H1 to H5 are generated by the electromagnet coils 20 to 24, respectively. These magnetic fields H
1 to H5 have the highest strengths of the magnetic fields H1 and H5, followed by the strengths of the magnetic fields H2 and H4, and then the magnetic field H3. Then, by combining these magnetic fields H1 to H5, the combined magnetic field H0 is formed to have a uniform magnetic flux density.

Therefore, a synthetic magnetic field H0 having a uniform magnetic flux density is formed in the plasma chamber 11 as shown in FIG. As a result, the reaction gas turned into plasma moves along the synthetic magnetic field H0 and passes through each nozzle hole 19 to be processed 13
To reach the top. That is, the active species at this time is the object 1 to be treated.
3 can be efficiently reached without deactivating, and
Is etched.

As described above, in the above embodiment, the reaction gas is supplied to the processing chamber 10 in which the object to be processed 13 is arranged,
When the reaction gas is turned into plasma to perform the etching process on the object to be processed 13, electric power corresponding to the number of turns of the electromagnet coils 20 to 24 arranged around the plasma chamber 11 is supplied to the inside of the plasma chamber 11. Since it is configured to generate a magnetic field having a uniform magnetic flux density, it is possible to generate a uniform density plasma in a wide area, and by changing the number of turns and the diameter of each electromagnet coil 20 to 24, the uniform density area can be generated. It can be adjusted arbitrarily. As a result, a uniform etching process can be performed on the entire surface of the semiconductor wafer having a large area.

The present invention is not limited to the above-mentioned one embodiment, and may be modified within the scope of the invention. For example, in the above embodiment, each electromagnet coil 20 to
A uniform magnetic flux density is obtained by changing the number of turns of 24, but the number of turns of each of the electromagnet coils 20 to 24 is made the same, and the voltage applied to these electromagnet coils 20 to 24 is applied differently according to the number of turns. Alternatively, a uniform magnetic flux density may be obtained. Also, the electromagnet coil must be at least the plasma chamber 1
It is only necessary to be arranged at two positions, that is, the upper end portion and the lower end portion of 1, and the number is not limited to five, and any plural number may be arranged. Further, the present invention can be applied not only to etching treatment but also to thin film formation.

[0018]

As described in detail above, according to the present invention, it is possible to provide a plasma etching processing apparatus capable of generating plasma of uniform density over a wide area.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a plasma etching processing apparatus according to the present invention.

FIG. 2 is an external view of an electromagnet coil of the same device.

FIG. 3 is a diagram showing a magnetic field formed by each electromagnet coil of the apparatus.

FIG. 4 is a diagram showing a magnetic field formed in a processing chamber of the apparatus.

FIG. 5 is a configuration diagram of a conventional device.

[Explanation of symbols]

10 ... Processing chamber, 11 ... Plasma chamber, 12 ... Etching chamber, 13 ... Object to be treated, 14 ... Gas introduction pipe, 15 ... Exhaust pipe, 16 ... Waveguide, 18 ... Nozzle plate, 19 ... Nozzle hole,
20 to 24 ... Electromagnetic coil, 26 ... DC power supply.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H05H 1/46 9014-2G

Claims (1)

[Claims] 1. A plasma processing apparatus for supplying a reaction gas to a plasma chamber in which an object to be processed is placed and converting the reaction gas into plasma to perform a predetermined process on the object to be processed. At least two electromagnet coils arranged around the lower end and power supply means for supplying electric power according to the number of turns of the electromagnet coils to generate a magnetic field having a uniform magnetic flux density in the plasma chamber are provided. A plasma processing apparatus characterized by the above.